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Optimization
and characterization of an extracellular proteases from
Aspergillus flavus ”MTCC 277”
Mukesh K. Upadhyay*, Rajesh Kumar,
Ajay Kumar, Shweta Gupta, Manju Kumari, Abhijeet Singh,
Devendra Jain and H. N. Verma
School of Life Sciences, Jaipur National University,
Jagatpura, Jaipur (Raj.)-302025, India.
*Corresponding author. E-mail:
mukeshfungi@gmail.com.
Accepted 22 June, 2010 |
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The present study was undertaken to describe the optimization
and characterization of proteases produced by, Aspergillus
flavus MTCC 277. This strain exhibited the highest protease
production after 4 days of incubation when grown on
casein-containing basal salt medium. The optimum temperature
of proteases was recorded at 35°C whereas optimum pH was 5
and 9. During the studies on the activity of enzyme with
metal ions at 50 and 100 mM, Zn2+, Co2+
and Fe2+ enhanced the enzyme activity and the
rest ions showed inhibitory effect. Amongst twelve solvents,
when used at the rate of 50 mM, formic acid showed maximum
inhibition (0.00 U/ml) followed by formaldehyde (1.45 U/ml)
and acetic acid (4.40 U/ml). Where as when the concentration
was increased to 100 mM of all solvents, it greatly
decreased the activity. A total of eight inhibitors were
studied and reported that EDTA highly inhibited (4.15 U/ml)
followed by urea (8.25 U/ml) and H2O2
(15.60 U/ml) at 50 mM concentration. When the concentration
was increased to 100 mM all the inhibitors greatly repressed
the activity. Zymographical analysis of this enzyme
indicated that there are two alleles/loci responsible for
proteases production and their relative mobility was P15.8
and P214.4.
Key
words:
Inhibitors, optimization, proteases, zymography.
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